Traditional port networks (PNs) are timed through fiber connections from a Center Stage Switch (CSS). Port Networks (PN) and Media Gateways (MG) that are connected via IP are timed through a local reference board. Media Gateways cannot interface to a CSS.
Use of a Network Timing Protocol (NTP) and Simple Network Timing Protocol (SNTP) require setting up a connection to a SNTP or NTP server which may not always be possible in certain environments, such as a private LAN.
GPS receivers are another method for maintaining synchronization, however GPS requires specialized receivers which must interface with the gateway. Therefore, this solution does require some hardware and software development.
IEEE 588 provides a high resolution based on dedicated hardware to provide a highly precise real-time clock in a time-stamp unit. A software module is used in conjunction with the dedicated hardware to handle the protocols and timing.